wil6210: fix race condition between BACK event and Rx data

While handling Rx packet, BACK event arrives and frees tid_ampdu_rx array.
This causes kernel panic while accessing already freed spinlock

The fix is to remove tid_ampdu_rx[]'s spinlock and instead use single
sta's spinlock to guard the whole tid_ampdu_rx array.

Signed-off-by: Dedy Lansky <qca_dlansky@qca.qualcomm.com>
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c b/drivers/net/wireless/ath/wil6210/debugfs.c
index e1f92763c209..21dc437b66a0 100644
--- a/drivers/net/wireless/ath/wil6210/debugfs.c
+++ b/drivers/net/wireless/ath/wil6210/debugfs.c
@@ -1059,6 +1059,7 @@ static int wil_sta_debugfs_show(struct seq_file *s, void *data)
 {
 	struct wil6210_priv *wil = s->private;
 	int i, tid;
+	unsigned long flags;
 
 	for (i = 0; i < ARRAY_SIZE(wil->sta); i++) {
 		struct wil_sta_info *p = &wil->sta[i];
@@ -1079,6 +1080,7 @@ static int wil_sta_debugfs_show(struct seq_file *s, void *data)
 			   (p->data_port_open ? " data_port_open" : ""));
 
 		if (p->status == wil_sta_connected) {
+			spin_lock_irqsave(&p->tid_rx_lock, flags);
 			for (tid = 0; tid < WIL_STA_TID_NUM; tid++) {
 				struct wil_tid_ampdu_rx *r = p->tid_rx[tid];
 
@@ -1087,6 +1089,7 @@ static int wil_sta_debugfs_show(struct seq_file *s, void *data)
 					wil_print_rxtid(s, r);
 				}
 			}
+			spin_unlock_irqrestore(&p->tid_rx_lock, flags);
 		}
 	}